877 research outputs found

    Grazing pressures and animal production from pearl millet cv. Comum

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    Um experimento visando avaliar o ganho médio diário (GMD) por animal, carga animal e ganho de peso vivo por hectare de animais cruza Zebu e cruza Charolês, acompanhado da avaliação da composição botânica, percentagem de proteína bruta (% PB) e digestibilidade in vitro da matéria orgânica (DIVMO) de milheto cv. Comum (Pennisetum americanum (L.) Leeke), sob diferentes pressões de pastejo (PP), foi conduzido na Estação Experimental Agronômica da UFRGS, Guaíba, RS, de 20.01.82 a 15.04.83. As PP eram constituídas de quatro níveis (4%, 6%, 8% e 10% do peso vivo PV) com distintos resíduos de MS na pastagem. Ocorreu uma redução na participação do milheto na composição botânica da pastagem nas maiores PP, compartilhando com acréscimos na participação de Cynodon dactylon (L.) Pers. Os GMD variaram de 0,50 kg a 1,24 kg por animal, evidenciando, para os animais cruza Zebu uma relação linear positiva com os resíduos médios de MS da pastagem. A carga animal e os ganhos por hectare variaram de 334 a 604 animais/dia/ha e 259 kg e 572 kg de peso vivo, respectivamente, com P > 05; contudo, não houve diferença significativa para esta variação na carga animal. Os valores para DIVMO e % PB estiveram entre 72% a 45% e 15% a 5,4%, respectivamente, ocorrendo diferença significativa (P .05 for animal/days/ha. The CP values decreased from 15% to 5.4% with dry matter residues causing a reduction in IVODM from 72% to 45% with a P <0.05 for the IVODM among the different periods.

    Volatilidade dos retornos econômicos associados à integração lavoura-pecuária no estado do Paraná

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    In the Brazilian agriculture, there is a great diversity and heterogeneity of production systems that are subject to wide number of factors of risks. Although these risks cannot be completely eliminated, they can be minimized by adopting some strategies, as the diversification with agricultural and cattle activities. Based on the research historical results of the Paraná’s agriculture e with the measurement of the value-at-risk, this work aimed to analyze the volatility of the economic returns of integrated crop-beef cattle systems compared to systems characterized by grain cultivation or beef cattle specialization. As results, we observed that, in the short-term, the integrated crop-livestock system is the alternative that trends to generate better economic results.Farm systems, Risk, Value-at-risk, Risk and Uncertainty,

    Avaliação da rebrota natural de pastagens de Trachypogon plumosus nos cerrados de Roraima

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    The natural regrowth of Trachypogon plumosus in native pasture of Roraima&acute;s savannas, was evaluated, during early rainy period. The parameters measured were dry matter (DM) yields and grass morphogenetic and structural characteristics. The experimental design was a completely randomized, with four replications. The treatments consisted of four cutting plants age (21, 35, 49, 63 and 77 days after beginning of the rainy period). Evaluations were carried out during the period of June to August of 2009. The green and dead DM, total number of tillers/plant, number of axillary tillers/plant, number of live tillers/plant, number of live leaves/tiller and leaf area were directly proportional to plant age. The leaf appearance and elongation rate were negatively affected by plant age, while the total DM was not affected by plant age. Considering the low green DM availability of T. plumosus, its recommends the utilization of some management practice, preferentialy grazing, to remove the dead DM with low nutrition value and permit a grass vigorous regrowth in the beginning of the rainy period.Avaliou-se a rebrota natural de Trachypogon plumosus em pastagens nativas dos lavrados de Roraima, no in&iacute;cio do per&iacute;odo chuvoso. Os par&acirc;metros mensurados foram rendimento de forragem e caracter&iacute;sticas morfog&ecirc;nicas e estruturais da gram&iacute;nea. Os tratamentos consistiram de cinco idades de rebrota (21, 35, 49, 63 e 77 dias decorridos o in&iacute;cio do per&iacute;odo chuvoso). O delineamento experimental foi inteiramente casualizados com quatro repeti&ccedil;&otilde;es. As avalia&ccedil;&otilde;es foram realizadas no per&iacute;odo de junho a agosto de 2009. Os rendimentos de mat&eacute;ria seca verde, n&uacute;mero total de perfilhos, n&uacute;mero de perfilhos axilares, n&uacute;mero de perfilhos vivos e &aacute;rea foliar foram diretamente proporcionais &agrave;s idades de rebrota, ocorrendo o inverso quanto ao rendimento de mat&eacute;ria seca morta, taxa de aparecimento e de expans&atilde;o de folhas, enquanto que os rendimentos de mat&eacute;ria total n&atilde;o foram afetados. Considerando-se a baixa disponibilidade de mat&eacute;ria seca verde de T. plumosus, recomenda-se a utiliza&ccedil;&atilde;o de alguma pr&aacute;tica de manejo, preferencialmente o pastejo, de modo a remover o material morto e de baixo valor nutritivo e permitir uma rebrota mais vigorosa da gram&iacute;nea no in&iacute;cio do per&iacute;odo chuvoso

    A pesquisa em Sistemas Integrados de Produção Agropecuária no Brasil

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    Integrated crop-livestock systems (ICLS) are designed to exploit synergisms and emergent properties resulting from interactions between different soil-plant-animal-atmosphere compartments that integrate themselves at different spatial-temporal scales. In this review, a panorama of the evolution of studies based on ICLS is presented. Specific keywords were used as search terms to construct a database of 450 articles from 93 national and international journals published up to and including 2013. These articles were classified according to the region of origin within Brazil (subtropical or tropical) and categorized regarding the studied components: soil, plant, animal and ‘others’. Within these components, groups of variables that could characterize the different thematic lines were listed. The number of publications worldwide has been increasing, and Brazil is one of the main suppliers of scientific work within this area. Although the number of scientific studies seeking better understanding of ICLS may have increased in Brazil, further studies with a systematic view and with larger temporal and spatial scales are still required to help identify interactions between diverse biotic and abiotic factors that define new properties that emerge from these systems.Os sistemas integrados de produção agrícola e pecuária são caracterizados como sistemas planejados para explorar sinergismos e propriedades emergentes, resultado de interações entre os diferentes compartimentos solo-plantaanimal- atmosfera, que se integram em diferentes escalas espaço-temporais. Nesta revisão é apresentado um panorama da evolução das pesquisas embasadas em uma produção integrada entre os diferentes compartimentos. Considerou-se o período até 2013 e palavras-chave como fator de busca, sendo construída uma base de dados, partindo de um universo de 450 artigos em 93 periódicos nacionais e internacionais. Estes artigos foram classificados de acordo com a região de origem do Brasil: subtropical ou tropical; e categorizados quanto aos componentes: solo, planta, animal e outros. Dentro desses componentes foram elencados grupos de variáveis que caracterizassem diferentes linhas temáticas. As publicações no mundo têm aumentado e o Brasil está entre os principais provedores de trabalhos científicos nessa área. Embora seja crescente o número de trabalhos científicos no Brasil, que buscam melhor compreensão dos sistemas integrados de produção agrícola e pecuária, as pesquisas com visão sistêmica e de maior escala temporal e espacial ainda necessitam de mais estudos, para que possam detectar interações entre os diversos fatores bióticos e abióticos e novas propriedades que emergem destes sistemas

    Soil Structural Quality and Relationships With Root Properties in Single and Integrated Farming Systems

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    Single farming systems (SFS) such as monocultures may negatively affect soil structural quality. This study tested the hypothesis that integrated farming systems (IFS), i.e., the combination of cropping and forestry and/or livestock farming, improves soil structural quality, root development and soil organic carbon. An experimental area was set up in 2012 at the Canguiri experimental farm belonging to the Federal University of Parana, Southern Brazil. The soils are predominantly Ferralsols. The experimental treatments representing different farming systems, organized in a random block design with three replicates, were: Forestry (F), Conventional Crop Production (C), Livestock (L), and integrated Crop-Forestry (CF), Crop-Livestock (CL), Livestock-Forestry (LF), and Crop-Livestock-Forestry (CLF). In situ measurements and sampling were carried out in the 0-0.3 m layer during summer 2019/20, and included soil penetration resistance (PR), soil structural quality based on visual evaluation of soil structure (Sq(VESS) scores), root length (RL), root volume (RV) and soil organic carbon content (SOC). Soil structural quality, penetration resistance, root length and volume, and SOC varied between farming systems, but no significant differences were found between single (C, L, F) and integrated farming systems (CF, CL, LF, CLF). The single system Forestry (F) and the integrated systems including forestry (LF, CF, CLF) tended to have higher Sq(VESS) scores, i.e. poorer soil structural quality, and higher PR, which we associate with the generally drier soil conditions that are due to higher soil water uptake and higher interception and reduce the frequency of wetting-drying cycles. Roots were concentrated in the shallow soil layer (0-0.1 m depth), and this was especially pronounced in the Crop (C) single farming system. Based on the measured values, our results suggest an acceptable soil structural quality in all farming systems. Our data revealed strong, significant relationships between soil structural quality, penetration resistance, root growth and SOC, demonstrating that improvements in soil structure results in lower soil penetration resistance, higher root volumes and higher SOC, and vice versa. Soil PR was positively correlated with Sq(VESS) (R-2 = 0.84), indicating that better soil structural quality resulted in lower soil mechanical resistance. This, in turn, increased root length and volume, which increases carbon input to soil and therefore increases SOC in the long run

    Raising Children’s Awareness about the Role of People on Supporting Sustainable Rural Land Use – Insights From Brazilian “Farm-School” Education Project

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    We proposed and evaluated a new approach (“Farm-school project”) to develop children's awareness about the role of people in agricultural production and environmental quality. The materialization of the “Farm-school” project was performed by a theoretical-practical 4-hour visit at an experimental farm. 240 Elementary school students were evaluated through concept maps and drawings, before and after the visit. There was a conceptual evolution in concept maps of 41 and 82%, and an increased number of categories per drawing of 23% and 37%. In concept maps, students did not relate people to the different spheres of agricultural production before the farm visit, but after, people became the main element. After the visit, students began to portray not only productive aspects in their drawings but also processes involving production, such as soil conservation practices and maintenance of mulch for soil cover. With the population concentrated in urban areas, there is a lack of contact with the rural landscape, generating a distorted view of food systems and rural land use, which affects social drivers and pro-environmental behavior. This imposes an educational task on governments to bring about information on agricultural production to elementary school students. We have proven the effectiveness of the “Farm-School” project as a low-cost educational policy alternative and a tool to increase children’s awareness about the role of people in agricultural production and environmental quality since students come to a better understanding of where food comes from and how it is produced.Propusemos e avaliamos uma nova abordagem (“projeto Fazenda na Escola”) para conscientizar as crianças sobre o papel das pessoas na produção agrícola e na qualidade ambiental. A materialização do projeto “Fazenda na escola” foi realizada por meio de uma visita teórico-prática de 4 horas em uma fazenda experimental. 240 alunos do ensino fundamental foram avaliados por meio de mapas conceituais e desenhos, antes e depois da visita. Houve evolução conceitual nos mapas conceituais de 41 e 82%, e aumento do número de categorias por desenho de 23% e 37%. Nos mapas conceituais, os alunos não relacionavam as pessoas com as diferentes esferas da produção agrícola antes da visita à fazenda, mas depois, as pessoas se tornaram o elemento principal. Após a visita, os alunos passaram a retratar não apenas aspectos produtivos em seus desenhos, mas também processos que envolvem a produção, como práticas de conservação do solo e manutenção da cobertura morta. Com a população concentrada nas áreas urbanas, há falta de contato com a paisagem rural, gerando uma visão distorcida dos sistemas alimentares e do uso do solo rural, o que afeta os motivadores sociais e o comportamento pró-ambiental. Isso impõe aos governos uma tarefa educacional de levar informações sobre a produção agrícola aos alunos do ensino fundamental. Comprovamos a eficácia do projeto “Fazenda na Escola” como uma alternativa de política educacional de baixo custo e uma ferramenta para aumentar a conscientização das crianças sobre o papel das pessoas na produção agrícola e na qualidade ambiental, pois os alunos passam a entender melhor de onde vem os alimentos e de como é produzido

    Estudio del fraccionamiento isotópico del nitrógeno aplicado a las gramíneas y leguminosas forrajeras

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    ResumenLos estudios de la composición isotópica del nitrógeno en el suelo y las plantas son importantes para identificar las diferencias en los procesos biogeoquímicos de reciclage de este elemento en los ecosistemas. Para evaluar la contribución de BNF, así como las diferencias en la capacidad de fijar y transferir N entre las especies de legumbres perennes y gramíneas existen varias técnicas que se han utilizado, como la reducción de acetileno, dilución isotópica 15N y abundancia natural de 15N. Sin embargo, las características responsables por estas variaciónes tienen que ser, en gran parte identificadas. Esta revisión tuvo como objetivo comparar la dinámica de la transferencia y la fijación de N de gramíneas y leguminosas forrajeras. Os estudos sobre composição isotópica de nitrogênio em solo e planta são importantes para identificar diferenças nos processos de ciclagem biogeoquímica deste elemento em ecossistemas. Para avaliar a contribuição da FBN, bem como, as diferenças na capacidade de fixar e transferir N entre espécies de leguminosas perenes e gramíneas existem várias técnicas que tem sido utilizadas, como a redução de acetileno, diluição isotópica de 15N e abundância natural de 15N. No entanto, as características responsáveis por estas variações precisam ser, em grande parte, identificadas. Esta revisão teve como objetivo comparar a dinâmica de transferência e fixação de N entre gramíneas e leguminosas forrageiras.AbstractStudies about isotopic composition of nitrogen in soil and plant matter to identify differences in biogeochemical cycling processes of this element in ecosystems. To assess the contribution of BNF, as well as differences in ability to fix and transfer N among species of perennial leguminous crops and grasses there are several techniques that have been used as the acetylene reduction, isotopic dilution 15N and 15N natural abundance. However, the features responsible for these changes need to be largely identified. This review aimed to compare the dynamics of transfer and fixing N between grasses and forage legumes.

    Conventional and alternative antifungal therapies to oral candidiasis

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    Candida-associated denture stomatitis is the most common form of oral candidal infection, with Candida albicans being the principal etiological agent. Candida adheres directly or via an intermediary layer of plaque-forming bacteria to denture acrylic. Despite antifungal therapy to treat denture stomatitis, infection is reestablished soon after the treatment ceases. In addition, many predisposing factors have been identified as important in the development of oral candidiasis, including malnourishment, common endocrine disorders, such as diabetis mellitus, antibacterial drug therapy, corticosteroids, radiotherapy and other immunocompromised conditions, such as acquired immunodeficiency syndrome (AIDS). These often results in increased tolerance to the most commonly used antifungals. So this review suggests new therapies to oral candidiasis.82483
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